Adjustable shelf for underneath staircases



FIG. 1 is an exploded bottom perspective view of an adjustable shelf for underneath staircases showing my new design;

FIG. 2 is a additional bottom perspective view thereof, with the broken-line disclosure of a portion of the underside of a staircase from which the shelf is intended to be suspended being for illustrative purposes only and forming no part of the claimed design; and,

FIG. 3 is a vertical cross-sectional view thereof, taken along line 3—3 of FIG. 2. 

The ornamental design for an adjustable shelf for underneath staircases, as shown and described. 